Efecto de la transformación de la selva a pradera sobre la dinámica de los nutrientes en un ecosistema tropical estancional en México

Abstract

The effects of conversion of tropical deciduous forest into pasture were examined on the Central Pacific Coast of Mexico. Under forested conditions two situations of nutrient cycles were determined: 1] hilltop locations where biological processes of soil were dominant; and 2] midslope locations where topographic characteristics were the main factor. When the forest cover was cut and burned, grasses were introduced for continuous cattle grazing, which led to changes in physical and chemical soil properties. Each topographic position responded differently to the conversion. The hilltop locations had higher nutrient retention capacity, which related strongly to higher soil organic matter content. In contrast, the midslope locations had a low nutrient protection capacity. After 11 years of use as pasture, the hilltop locations lost 700 kg N ha-1, 2,500 kg Ca ha-1 and 500 kg P ha-1, similar to the midslope locations losses.